Unleash the belch-roars! What to expect as elephant seal bulls return to SLO County beach
Friends of the Elephant Seal holds a contest every year to guess when the first bull will arrive for the breeding season.
The prize is the satisfaction of guessing right and being praised by FES members and elephant-seal admirers. Which is the main point, and the most fun!
Want to take part? Submit your guess at mailchi.mp/elephantseal.org/firstbull2024.
What happens as elephant seal bulls arrive for breeding season?
The arrival is typically quiet, as a bull surfs in on a wave.
He’ll galumph a few times onto the beach, then slump down. His huge body, supported by buoyancy in the water, now feels the weight of gravity. Transition to living on land is difficult.
The remaining seals on the beach are juveniles who haven’t yet departed after their fall haul-out.
The arrival of mature bulls usually clears nearly all of them off the beach.
The juveniles have rested on the beach since September. Time now for them to go on their second migration of the year. They will forage and grow bigger, become more mature. Females may enter the breeding population, getting pregnant for the first time. Young males will return next year, with the oldest joining the mature bulls and taking a place in the dominance hierarchy.
After the shock of arriving on the beach, bulls announce themselves.
They are among the loudest animals on earth. They need to be.
A bull needs his threat vocalization — also called a clap-threat or a belch-roar — to intimidate opponents far and wide. The threat can carry around 75 feet, over the background noise of wind and waves. I’ve heard bellows echoing farther than that, an eerie call as darkness covers the beach.
At a recent evening event at the Piedras Blancas light station, the elephant seal calls added to the sense of being in a strange other world.
A bull will raise himself up, his chest shield thrust forward, holding himself up on his flippers, open his mouth and let ‘er rip. Each bull has an individual call, identifying him to other bulls. If they’ve fought before, no need to fight again. They establish themselves in the dominance hierarchy. They can remember who beat who for years.
As the elephant seals have increased in numbers, bulls’ calls have become more complex. This may have happened because of the larger numbers and the need to identify themselves as individuals.
What are they fighting for?
Only the dominant bulls, the beachmasters, get to breed, so there’s a lot at stake.
By the peak of the breeding season in January and February, around 235 beachmasters will reign over harems of 30-40 females at Piedras Blancas.
The bulls are at their largest physical bulk now, after months of feeding along the North American continental shelf. They’ll need it to get through to March without eating.
Bulls stop feeding when they leave their foraging grounds and head south for the breeding beaches.
They’ve been eating fish and squid, gaining as much as 28 pounds a day, since they left the Central Coast in August and September. They need enough blubber to survive 100 days or more, to the end of the breeding season. They are huge now, but will get thin over the coming months.
Look for long noses and big pink chest shields on massive bodies. They surf out onto the sand, their massive weight now subject to gravity instead of supported by water. Welcome to life on land!
Every bull on the beach is a survivor in a tough world. Only about 1% of male pups born reach breeding age. Surviving is essential, and those tough enough and lucky enough will have two to four good years to breed.
Surviving isn’t enough to guarantee breeding, though. They jockey for dominance and breeding rights. Two-thirds of the bulls, the less dominant ones, don’t get to breed at all.
Early arrivals find enough beach to separate them, but they fight to establish the dominance hierarchy. It’s relatively stable, but always subject to change. As new bulls arrive, and bulls move from beach to beach, any beachmaster may be defeated.
The dominance hierarchy dictates breeding rights. Males fight for dominance and to defend their harem of females. They arrive looking for a fight, and it only gets worse.
Size is an advantage but not the only factor.
The alpha bull, the beachmaster, is frequently challenged by other bulls. He can lose a battle and lose his place in the dominance hierarchy. A deposed bull may fall so low in the dominance hierarchy that he loses all breeding rights that season.
Beachmasters are vigilant about chasing other bulls away from the harem, but it’s a constant challenge. All bulls are focused on mating, regardless of their status in the beach hierarchy.
Lower-ranking bulls sneak around the harem and try to mate with females. They sometimes get away with it.
Fights can be brief encounters, an exchange of threats, or they can be violent struggles that go on for half an hour or more. Bulls may start fighting on the beach and continue fighting in the water.
They rear up and rip and tear at each other. The chest shield provides some protection, a calloused area that bleeds but is not life-threatening. Wounds can be severe, but immediate death is rare. Some bulls may escape to the sea and die of their wounds later.
Visiting the Viewpoint
The arrival of the full-grown bulls heralds the most exciting season at the rookery.
The parking lot has been maintained in good condition. Friends of the Elephant Seal docents are available every day to answer questions.
Check the live webcam to see what’s happening on the beach at elephantseal.org/live-view.
Maybe today’s the day to drive up Highway 1 to see the seals. Highway 1 is open only as far north as Lucia Lodge.
It remains closed due to the Regent Slide between Lucia Lodge and Esalen Institute.
Bring your camera. Always open, always free. One of the spectacular advantages of California’s Central Coast.
